CN101834523B - High pressure pulse generating system for obtaining random-wave-form forced response and working procedure thereof - Google Patents

Abstract

The invention relates to a high-voltage pulse generating system and a working method thereof for obtaining an excitation response of an arbitrary waveform, wherein the high-voltage pulse generating system includes: 1) a high-voltage pulse generating circuit for generating a signal for exciting a structure to be measured and a synchronous trigger signal; PXI interface structure for providing power; 3) DC/DC booster circuit for obtaining high DC voltage. The generating system and its working method of the present invention have the following technical effects: 1) the efficiency of non-destructive testing is improved, and the equipment cost is reduced; 2) the equivalent response of multiple arbitrary waveforms can be obtained with only one excitation, which can be more flexibly The detection signal is processed for data, which improves the effectiveness of data use; 3) The power is boosted through the PXI interface, which is convenient for compatible use with other computer systems and virtual instruments, and the system structure is simple.

Description

Obtain high pressure pulse generating system and the method for work thereof of random-wave-form forced response

Technical field

The present invention relates to a kind of high pressure pulse generating system and method for work thereof that obtains random-wave-form forced response, belong to the Ultrasonic NDT field.

Background technology

Ultrasonic NDT art (UT) is a kind of important method of object Non-Destructive Testing, almost is applied to all industrial departments.Compare with other conventional Dynamic Non-Destruction Measurement, it is wide that it has the detected object scope, and it is large to detect the degree of depth; Defect location is accurate, and is highly sensitive; Cost is low, and work is convenient; Speed is fast, and is harmless and be convenient to the characteristics such as on-the-spot use.

Utilize ultrasonic wave to can't harm when occuring, generally adopt two kinds of forms of step pulse wide-band excitation and specific waveforms arrowband excitation.The extraction that the excitation of specific waveforms arrowband helps to improve the ultrasonic image-forming system resolving power and is convenient to signal characteristic, in fields such as the generation of composite structure Lamb ripple and xoncrete structure imaging generations, this technology has broad application prospects.Be CN1355081 at publication number, denomination of invention is a kind of with in the patent of electric arc method for exciting ultrasonic waves, the hyperacoustic method of a kind of generation is disclosed, utilize the load characteristic of conventional electric arc, under the driving that possesses good dynamic characteristic power supply, free electric arc or plasma-arc are applied high frequency modulated, make the electric arc as the processing thermal source, become simultaneously a kind of controlled ultrasonic wave emission source; This ultrasonic wave emission source effective object is metal structure, is not suitable for xoncrete structure; And complicated structure.At Japan Patent G01N 29/22.UDAGAWA, a kind of exciting circuit of ultrasonic probe is disclosed among the Yoshio.ULTRASONIC PROBE EXC ITATION CIRCUIT., have the spike characteristic although wherein produce ultrasonic wave, its effect is the echo in the compensation metal crack; And this circuit can not use with virtual instrument is compatible.

Under present existing technology, produce specific excitation waveform such as need, need to adopt function signal to produce the method that circuit adds power amplifier.The generation systems that adopts this method to consist of, required hardware is many, and volume is larger.The generation systems that has adopts transformer to boost, and transformer not only volume is large, and certain frequency limitation is arranged.These class methods can be brought a lot of inconvenience for large-area detection, and instrument is difficult for mobile, and require the supply civil power, affect detection efficiency.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art part, provide that a kind of volume is little, driving voltage is high, be convenient to virtual instrument system use, can be by efficient high pressure pulse generating system and the method for work thereof that obtains random waveform signal equivalence exciter response of excitation once.

The high pressure pulse generating system of acquisition random-wave-form forced response of the present invention comprises:

1) high-voltage pulse for generation of the tested architecture signals of excitation and synchronous triggering signal produces circuit;

2) for the PXI interface structure that power supply is provided;

3) for the DC/DC booster circuit that obtains dc high voltage;

4) be used for the control module of acceptance response signal;

5) be used for obtaining the control module that random waveform responds from the conversion of high pressure exciter response;

Wherein above-mentioned all circuit and structure are all based on the PXI bus, said high-voltage pulse produces circuit and comprises for generation of the adjustable high-voltage pulse signal of pulsewidth and the capacitor charge and discharge circuit of synchronous triggering signal, is used for the discharge switch of control capacitance charge-discharge circuit and is used for the multi resonant circuits for triggering that control discharges and recharges the cycle.

More preferably, in the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention, the trigger pulse width of said multi resonant circuits for triggering is 100ms～1 μ s; Trigger pulse width can be regulated; The rising edge of trigger impulse is steep, and the rise time is not more than 20ns; The work of trigger impulse control mercury relay, trigger impulse has certain load capacity, guarantees the normal operation of mercury relay; Synchronizing cycle is adjustable in 100Hz～500Hz scope.

The method of work of the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention may further comprise the steps:

1) high-voltage pulse occurs: produce controlled high-voltage pulse signal of cycle by multi resonant circuits for triggering control mercury relay and charge-discharge circuit; Produce dc high voltage, conditioning signal voltage by the DC/DC booster circuit;

2) encourage tested test block: with the high-voltage pulse signal that produces in the previous step, export the ultrasonic action transducer to by bnc interface, tested test block is applied step signal encourage;

3) acceptance response signal: the step response s (t) that is obtained tested test block by Ultrasonic Testing Transducer; Step response s (t) differential of tested test block is obtained unit impulse response h (t), and this unit impulse response can repeatedly be used, and is shown below:

$h\left(t\right)=\frac{d}{\mathrm{dt}}s\left(t\right)$ Formula (1)

In the formula (1), h (t) is unit impulse response, and s (t) is step response, d be s (t) to the differential of t, dt is the unit interval variable;

4) the corresponding conversion of arbitrary excitation, the random waveform signal g (t) of the following form of usefulness computer Software Create:

Exp ((t/a) for g (t)=Acos (2 π ft) ²) formula (2)

In the formula (2), g (t) is the random waveform signal, and A is signal amplitude, and f is signal frequency, and a is the signal envelope width, and t is time variable, and A, f that can be by changing pumping signal, a be the conversion waveform signal arbitrarily;

5) equivalent signal response: the convolution by random waveform signal g (t) and unit impulse response h (t) obtains random waveform equivalent signal response y (t), can be defined by following integrated form:

$y\left(t\right)=g\left(t\right)*h\left(t\right)={\∫}_{-\∞}^{\∞}h\left(\mathrm{\τ}\right)g(t-\mathrm{\τ})\mathrm{d\τ}$ Formula (3),

In the formula (3), * represent convolution, y (t) is random waveform equivalence exciter response, g (t) is the random waveform signal, and h (t) is unit impulse response, and t is time variable, τ is parametric variable, h (τ) is the unit impulse response function of τ for independent variable, and g (t-τ) is the rear function of random waveform signal counter-rotating displacement, and d τ is the unit parameter variable;

6) finish.

Random waveform excitation equivalence response refers to it be carried out data process by behind the tested structural response of set of pulses excitation acquisition, obtains by the response of geodesic structure to other random waveforms by algorithm.Its principle is: (1) adopts the two exponential wave pulse-generating circuits excitation ultrasonic transducers of high pressure and by geodesic structure, obtain the ultrasonic response signal of structure, this signal is carried out the unit impulse response that conversion obtains system, utilize linear system that the response of any input is equaled the principle of this input and unit impulse response convolution, obtain the equivalence response to the arbitrary excitation signal.(2) provide power supply by the PXI interface, utilize the DC-DC acquisition dc high voltage that boosts, utilize mercury relay to control noninductive capacitor charge and discharge and produce controlled high-voltage pulse.

The invention provides a kind of high pressure pulse generating system and method for work thereof of efficient acquisition random-wave-form forced response, with respect to prior art, have following technique effect:

1) improved the efficient of Non-Destructive Testing, needn't adopt arbitrarily signal generating device and power amplifier, system consists of simple, has reduced equipment cost;

2) only need once excitation can obtain the equivalence response of multiple random waveform, can carry out data to detection signal more flexibly and process, improved the validity that data are used;

3) boost by the power taking of PXI interface, be convenient to unify with other departments of computer science that virtual instrument is compatible to be used, system consists of simple.

Description of drawings

Fig. 1 is the structural representation of the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention;

Fig. 2 is the workflow diagram of the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention;

Fig. 3 is the algorithm of the high pressure pulse generating system course of work of acquisition random-wave-form forced response of the present invention;

Fig. 4 is the effect comparison figure of the present invention and prior art.

Embodiment

Embodiment 1

Such as Fig. 1, Fig. 2, shown in Figure 3, the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention comprises: 1) be used for the high-voltage pulse generation circuit that the excitation high-voltage pulse produces; 2) for the PXI interface structure that power supply is provided; 3) for the DC/DC booster circuit that obtains dc high voltage; Wherein above-mentioned all circuit and structure are all based on the PXI bus, said high-voltage pulse produces circuit and comprises for generation of the adjustable high-voltage pulse signal of pulsewidth and the capacitor charge and discharge circuit of synchronous triggering signal, is used for the discharge switch of control capacitance charge-discharge circuit and is used for the multi resonant circuits for triggering that control discharges and recharges the cycle.In the present embodiment, used discharge switch is enough large and QA mercury relaies of energy of reasonable selection withstand voltage, and this mercury relay is 50 Ω build-out resistor types, and maximum switched voltage is 1000V, and maximum switch current is 1A.Be 2ms its operate time, is 50ms owing to the continuous impulse generation time interval of generation systems is long, so also meet the demands its operate time, its volume is also very little simultaneously.Its drive circuit is to adopt 555 timers to realize, it can produce the adjustable pulse signal of pulsewidth and regulate the cycle that high-voltage pulse produces.

The trigger pulse width of used multi resonant circuits for triggering is 100ms～1 μ s; Trigger pulse width can be regulated; The rising edge of trigger impulse is steep, and the rise time is not more than 20ns; The work of trigger impulse control mercury relay, trigger impulse has certain load capacity, guarantees the normal operation of mercury relay; Synchronizing cycle is adjustable in 100Hz～500Hz scope.

The method of work of the high pressure pulse generating system of acquisition random-wave-form forced response of the present invention may further comprise the steps:

1) high-voltage pulse occurs: produce controlled high-voltage pulse signal of cycle by multi resonant circuits for triggering control mercury relay and charge-discharge circuit, the high voltage pulse source produces fast forward position (about 20ns) and slow rear pulse signal along (100ms～1 μ s), export the ultrasonic action transducer to by bnc interface, capacitor charge and discharge circuit produces the main circuit of high-voltage pulse, it is in charged state always, when mercury relay moves, circuit begins the high-voltage pulse that discharge generation needs, and is wherein controlled by the multi resonant circuits for triggering operate time of mercury relay.During use, can implement single activation by manual control, also can pass through periodically controlled discharge switch generation cycle high-voltage pulse of multi resonant circuits for triggering, its discharge cycle can be regulated by control triggering electric circuit the length in its cycle.When needs conditioning signal voltage, can pass through boost module circuit adjustment signal voltage; Decay produces the Transistor-Transistor Logic level lock-out pulse to high pressure, can access high-speed collection card triggering collection passage and use.

2) encourage tested test block: with the high-voltage pulse signal that produces in the previous step, export the ultrasonic action transducer to by bnc interface, tested test block is applied step signal encourage;

3) acceptance response signal: the step response s (t) that is obtained tested test block by Ultrasonic Testing Transducer; Step response s (t) differential of tested test block is obtained unit impulse response h (t), and this unit impulse response can repeatedly be used, and is shown below:

$h\left(t\right)=\frac{d}{\mathrm{dt}}s\left(t\right)$ Formula (1)

In the formula (1), h (t) is unit impulse response, and s (t) is step response, d be s (t) to the differential of t, dt is the unit interval variable;

4) the corresponding conversion of arbitrary excitation, the random waveform signal g (t) of the following form of usefulness computer Software Create:

Exp ((t/a) for g (t)=Acos (2 π ft) ²) formula (2)

In the formula (2), g (t) is the random waveform signal, and A is signal amplitude, and f is signal frequency, and a is the signal envelope width, and t is time variable, and A, f that can be by changing pumping signal, a be the conversion waveform signal arbitrarily;

5) equivalent signal response: the convolution by random waveform signal g (t) and unit impulse response h (t) obtains random waveform equivalent signal response y (t), can be defined by following integrated form:

$y\left(t\right)=g\left(t\right)*h\left(t\right)={\∫}_{-\∞}^{\∞}h\left(\mathrm{\τ}\right)g(t-\mathrm{\τ})\mathrm{d\τ}$ Formula (3),

In the formula (3), * represent convolution, y (t) is random waveform equivalence exciter response, g (t) is the random waveform signal, and h (t) is unit impulse response, and t is time variable, τ is parametric variable, h (τ) is the unit impulse response function of τ for independent variable, and g (t-τ) is the rear function of random waveform signal counter-rotating displacement, and d τ is the unit parameter variable;

6) finish.

Embodiment 2

With the effect comparison that carries out of the system and method for embodiment 1 and prior art, as shown in Figure 4, solid line represents actual modulated wave response curve, and the pulse that is namely produced by function generator and power amplifier is to by the exciter response of geodesic structure.Dotted line represents equivalent modulating wave response curve, and the pulse that is namely produced by system and method for the present invention is to by the geodesic structure exciter response.Wherein, abscissa represents sampling number, and ordinate represents the relative amplitude of curve.By finding out on the figure, actual modulated wave response curve overlaps substantially with the response curve that produces with native system and method.Be that native system and method can substitute other labyrinths such as existing function generator and power amplifier fully.

Claims (3)

1. obtain the high pressure pulse generating system of random-wave-form forced response, it is characterized in that, comprising:

1) high-voltage pulse for generation of the tested architecture signals of excitation and synchronous triggering signal produces circuit;

2) for the PXI interface structure that power supply is provided;

3) for the DC/DC booster circuit that obtains dc high voltage;

4) for the control module of acceptance response signal, the said control module course of work is as follows:

Acceptance response signal: the step response s (t) that is obtained tested test block by Ultrasonic Testing Transducer; Step response s (t) differential of tested test block is obtained unit impulse response h (t), and this unit impulse response can repeatedly be used, and is shown below:

Formula (1)

In the formula (1), h (t) is unit impulse response, and s (t) is step response, d be s (t) to the differential of t, dt is the unit interval variable;

5) be used for obtaining the control module that random waveform responds from the conversion of high pressure exciter response, the said control module course of work is as follows:

The corresponding conversion of arbitrary excitation, the random waveform signal g (t) of the following form of usefulness computer Software Create:

Exp ((t/a) for g (t)=Acos (2 π ft) ²) formula (2)

In the formula (2), g (t) is the random waveform signal, and A is signal amplitude, and f is signal frequency, and a is the signal envelope width, and t is time variable, and A, f that can be by changing pumping signal, a be the conversion waveform signal arbitrarily,

Wherein above-mentioned all circuit and structure are all based on the PXI bus, said high-voltage pulse produces circuit and comprises for generation of the adjustable high-voltage pulse signal of pulsewidth and the capacitor charge and discharge circuit of synchronous triggering signal, is used for the discharge switch of control capacitance charge-discharge circuit and is used for the multi resonant circuits for triggering that control discharges and recharges the cycle.

2. the high pressure pulse generating system of acquisition random-wave-form forced response according to claim 1 is characterized in that, the trigger pulse width of said multi resonant circuits for triggering is 100ms～1 μ s; Trigger pulse width can be regulated; The rising edge of trigger impulse is steep, and the rise time is not more than 20ns; Synchronizing cycle is adjustable in 100Hz～500Hz scope.

3. obtain the method for work of the high pressure pulse generating system of random-wave-form forced response, it is characterized in that, may further comprise the steps:

1) high-voltage pulse occurs: produce controlled high-voltage pulse signal of cycle by multi resonant circuits for triggering control mercury relay and charge-discharge circuit; Produce dc high voltage, conditioning signal voltage by the DC/DC booster circuit;

2) encourage tested test block: with the high-voltage pulse signal that produces in the previous step, export the ultrasonic action transducer to by bnc interface, tested test block is applied step signal encourage;

3) acceptance response signal: the step response s (t) that is obtained tested test block by Ultrasonic Testing Transducer; Step response s (t) differential of tested test block is obtained unit impulse response h (t), and this unit impulse response can repeatedly be used, and is shown below:

Formula (1)

In the formula (1), h (t) is unit impulse response, and s (t) is step response, d be s (t) to the differential of t, dt is the unit interval variable;

4) the corresponding conversion of arbitrary excitation, the random waveform signal g (t) of the following form of usefulness computer Software Create:

Exp ((t/a) for g (t)=Acos (2 π ft) ²) formula (2)

In the formula (2), g (t) is the random waveform signal, and A is signal amplitude, and f is signal frequency, and a is the signal envelope width, and t is time variable, and A, f that can be by changing pumping signal, a be the conversion waveform signal arbitrarily;

5) equivalent signal response: the convolution by random waveform signal g (t) and unit impulse response h (t) obtains random waveform equivalent signal response y (t), can be defined by following integrated form:

Formula (3),

In the formula (3), * represent convolution, y (t) is random waveform equivalence exciter response, g (t) is the random waveform signal, and h (t) is unit impulse response, and t is time variable, τ is parametric variable, h (τ) is the unit impulse response function of τ for independent variable, and g (t-τ) is the rear function of random waveform signal counter-rotating displacement, and d τ is the unit parameter variable;

6) finish.

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